Recent studies state that patients affected by aneurysmal subarachnoid hemorrhage (aSAH) today survive longer because they are treated early. Unfortunately, patients often develop chronic disabling neurological deficits at a rate that is still unacceptable given the progress in the specific treatment of this pathology and the volume of systems of neurological monitoring available to date in Italy. The main cause of unfavorable neurological outcome is delayed cerebral ischemia (DCI), often resulting from symptomatic vasospasm defined as delayed neurological ischemic deficit (DIND). The incidence of DIND is not defined and is difficult to diagnose early as there is no gold standard for identifying it, nor guidelines regarding the most effective treatment. Given these gaps, the primary objective of this study is to describe the incidence of DIND in patients affected by aSAH, collecting information regarding the diagnostic imaging (neurological symptom on clinical examination or alteration on instrumental monitoring). Secondary objectives will be to evaluate the different therapeutic strategies adopted in the different participating centers and compare these strategies to mortality and short- and long-term functional neurological outcome. Furthermore, as there are no data in the literature, the Investigators want to describe the indications, usefulness and intensity of treatment in the aSAH patient in case of monitoring of parenchymal intracranial pressure.